Friday, July 9, 2010

What is a Passive House?

What exactly is a passive house ? A refuge for passive-aggressives? A space where the lights are out all the time and its inhabitants sit in quiet contemplation before a burning candle? Well, actually none of the above.

I was hoping to find out more about passive houses at a talk presented by Build It Green in Berkeley. Build It Green, a nonprofit membership organization that offers training and certifications in green building from Sacramento to Downey, California.

Amid a lovely dinner served with ample bottles of thirst-quenching waters and sparkling ciders at Truitt & White, a roomful of building types gathered to hear more about the building of the first Passive House in California on a land trust in West Marin County at 11560 California 1.

According to Build It Green, about 20,000 passive houses have been designed, built and retrofitted over the last 10 years in Europe, 12 in the United States, and one in California, which may offer another reason to drive to Pt. Reyes.  

Most simply put, a Passive House receives and captures energy. In doing so, it slashes heating and energy costs by 90 percent. Of course this is a loosey-goosey definition.

There are Passive House standards that a building must meet to be certified. The Passive House Planning Package (PHPP), is a software package constructed like the popular TurboTax income tax program, allowing builders to plug in numbers and to receive automatic calculations for projections of  heat load, loss, and energy usage with updated calculations for climates around the world.  It’s a package that continually improves with updated data.

Here’s a bit of history. The notion of the Passive House (“Passivhaus”) was first developed in Germany in the early 1990s by Professors Bo Adamson of Sweden and Wolfgang Feist of Germany. They put together solar design ideas from North America with “low energy” European building standards to create the notion of a house that could maintain a comfortable interior climate without conventional heating and cooling systems. A Passive House can be operated without the help of large “active” mechanical systems (i.e. furnaces and boilers), thus the “Passive” moniker.

In 2003, Katrin Klingenberg, a German designer, built the first Passive House in Urbana, Illinois. Klingenberg established the Passive House Institute U.S. (PHIUS) in Urbana with builder Mike Kernagis. In January 2008, PHIUS was authorized by the Passivhaus Institut in Darmstadt as the official certifier of Passive Houses in the U.S.

Got it? Now back to Berkeley where James Bill, Katy Hollbacher, and Terry Nordbye, architect,engineer, and builder who worked together on West Marin’s Blue2 House, discussed what it took to build California’s first certified Passive House that soon will be occupied by a family. All agreed that the Passive House model goes far beyond Energy Star standards, a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy’s effort toward more cost effective environmental solutions. “In the past compliance, not energy usage, is what people looked at,” said Hollbacher.

Retrofitting an entire home to meet Passive House standards may not be cost effective for the average homeowner in the temperate Bay Area. However, the Build It Green presenters agreed that incorporating different aspects of the PHPP methodology may be the incremental best way to go.

In any case, it's going, going, going green. 

Lenore Weiss

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